1. Field of the Invention
The present invention relates to organo-transition metal compounds. More specifically, the present invention relates to a series of substituted bicycloalkene-palladium compounds having utility as vinyl addition polymerization catalysts. This invention also relates to methods of making these compounds.
2. Description of the Art
Cyclic olefin polymers, such as polynorbornenes (PNBs), are widely used in a variety of electronic, optoelectronic and other applications, and therefore, methods of making such PNBs in an industrial scale are gaining importance. It is well known in the literature that various functionalized PNBs can be synthesized by employing suitable starting norbornene monomers by vinyl addition polymerization using a variety of transition metal catalysts and procatalysts. See for example, U.S. Pat. No. 7,989,570, pertinent portions of which are incorporated herein by reference.
However, in order to manufacture functionalized PNBs in an industrial scale, there is a need for catalyst or catalyst system to meet certain desirable characteristics. A few of such characteristics, include among others, a) a living catalyst polymerization system, that is, the catalyst retains its activity even after reaching very high degree of chain growth leading to very high molecular weight polymer; b) high activity of the catalysts system even at a very high monomer to catalyst molar ratio; c) effective chain transfer to control molecular weight; d) good catalyst stability during polymerization, including thermal and chemical stability, that is, no termination of the polymerization activity; e) fast polymerization kinetics, that is, fast chain propagation preferably at around room temperature; and f) storage stable components, such as for example, stable A and B components, for highly reactive catalyst systems.
U.S. Pat. No. 6,936,672 discloses a variety of catalysts, procatalysts, and catalyst systems for the polymerization of polycyclic olefins. However, these catalyst systems may not be suitable for the preparation of highly ordered block copolymers as described herein.
Accordingly, it is an object of this invention to provide a series of substituted or unsubstituted bicycloalkene-palladium compounds having utility as vinyl addition polymerization catalysts as a single component or a bicomponent system, which are useful as living vinyl addition polymerization catalysts for the preparation of a variety of homopolymers as well as block polymers encompassing functionalized (i.e., polar and non-polar monomers) norbornene monomers.
It is also an object of this invention to provide processes for the preparation of the substituted bicycloalkene-palladium compounds as disclosed herein.
It is further an object of this invention to provide a series of novel block copolymers having unique properties for a variety of applications in the fabrication of electronic, optoelectronic devices and for the formation of membranes having unique properties for a variety of applications.
Other objects and further scope of the applicability of the present invention will become apparent from the detailed description that follows.